Hot Water Device for Bathtub

ABSTRACT

The present invention provides a hot water device for bathtub in which water is not wasted to allow energy saving and at the same time it is possible to save a trouble of adjusting the temperature of water for bathtub supplied to the bathtub to a temperature desired by the user during bathing. In the hot water device for bathtub of the invention, the water for bathtub having its temperature varied by the controller to temperature desired by the user during bathing is supplied to a bathtub. Accordingly, the temperature adjustment using hot water is not needed, and thus water is not wasted to allow energy saving and at the same time it is possible to save a trouble of adjusting the temperature of hot water in the bathtub to a temperature desired by the user during bathing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hot water device for bathtub for homeor professional use.

2. Description of the Related Art

As a hot water device for bathtub of this type, there has been known onewhich includes a hot water storage tank which stores high-temperaturewater, water supplying means for supplying low-temperature water, atemperature sensor which detects an outdoor air temperature, a timerwhich detects a time zone of day, and control means for controlling theoperation of a compressor (for example, Japanese Patent Publication2001-201177).

In the hot water device for bathtub having the above configuration, thecontrol means controls the operation of the compressor based on anoutdoor air temperature detected by the temperature sensor and a timezone of day detected by the timer, whereby high-temperature water isstored in the hot water storage tank.

However, in the hot water device for bathtub, while energy saving instoring high-temperature water in the hot water storage tank isconsidered, no consideration is given to energy saving in using hightemperature water stored in the hot water storage tank.

Particularly, in the hot water device for bathtub, high-temperaturewater stored in the hot water storage tank and low-temperature watersupplied from the water supplying means are mixed to obtain water forbathtub of a preliminarily determined preset temperature, and thereafterthe water for bathtub of the preset temperature is supplied to thebathtub. However, for example, when the outdoor air temperature is highin summer or the like, the preset temperature of water for bathtub maybe higher than a temperature desired by the user during bathing. In thiscase, adjustment must be made to obtain the temperature desired by theuser by further supplying low-temperature water from the water supplyingmeans to the bathtub. Similarly, for example, when the outdoor airtemperature is low in winter or the like, the preset temperature ofwater for bathtub may be lower than a temperature desired by the userduring bathing. In this case, adjustment must be made to obtain thetemperature desired by the user by further supplying high-temperaturewater stored in the hot water storage tank to the bathtub.

That is, in the hot water device for bathtub, it takes labor to adjustthe temperature of water for bathtub supplied to the bathtub to atemperature desired by the user during bathing, and at the same timewater consumption in adjusting the temperature of water for bathtubincreases, so energy saving cannot be achieved.

BRIEF SUMMARY OF THE INVENTION

The present invention has been achieved in view of the above-mentionedcircumstances, and has an object to provide a hot water device forbathtub in which water is not wasted to allow energy saving and at thesame time it is possible to save a trouble of adjusting the temperatureof water for bathtub supplied to the bathtub to a temperature desired bythe user during bathing.

According to the present invention, there is provided a hot water devicefor bathtub which includes a hot water storage tank which storeshigh-temperature water, water supplying means for supplyinglow-temperature water, and temperature setting means allowing setting ofthe temperature of water for bathtub to be supplied to a bathtub, thehot water device for bathtub mixing high-temperature water supplied fromthe hot water storage tank and low-temperature water supplied from thewater supplying means and then supplying water for bathtub of a presettemperature to the bathtub, and the hot water device for bathtubincluding outdoor air temperature information acquiring means foracquiring prescribed information on outdoor air temperature, and controlmeans for varying the temperature of water for bathtub to a temperaturelower than the preset temperature when the outside air temperatureacquired by the outdoor air temperature information acquiring means ishigher than a prescribed reference temperature, or varying thetemperature of water for bathtub to a temperature higher than the presettemperature when the outside air temperature acquired by the outdoor airtemperature information acquiring means is lower than the prescribedreference temperature.

According to the inventive hot water device for bathtub, prescribedinformation on outdoor air temperature is acquired by the outdoor airtemperature information acquiring means, and when the outdoor airtemperature acquired by the outdoor air temperature informationacquiring means is higher or lower than a prescribed referencetemperature, water for bathtub having its temperature varied by thecontrol means to a temperature desired by the user during bathing issupplied to the bathtub.

Accordingly, temperature adjustment which uses water is not needed, sowater is not wasted to achieve energy saving, and at the same time it ispossible to save a trouble of adjusting the water in the bathtub to atemperature desired by the user during bathing.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic configuration view of a hot water device forbathtub according to an embodiment of the present invention; and

FIG. 2 is a flowchart illustrating the control of the hot water devicefor bathtub.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 illustrate a hot water device for bathtub according to anembodiment of the present invention. The hot water device for bathtubincludes: a refrigerant circuit 10 in which refrigerant circulates; hotwater circuit 20 in which hot water circulates; a hot water storage tank30 which stores high-temperature water; water supplying tube 40 actingas means for supplying low-temperature water; a mixing valve 50 whichmixes high-temperature water supplied from the hot water storage tank 30and low-temperature water supplied from the water supplying tube 40; aremote controller 60 acting as temperature setting means allowingsetting of the temperature of water for bathtub to be supplied to alater described bathtub 51; an outdoor air temperature sensor 70 actingas outdoor air temperature information acquiring means for acquiringinformation on outdoor air temperature; and a controller 80 acting ascontrol means.

The refrigerant circuit 10 is constituted of a compressor 11, anexpansion valve 12 acting as an expansion mechanism, an air heatexchanger 13 and a water heat exchanger 15; refrigerant circulatesthrough the compressor 11, the water heat exchanger 15, the expansionvalve 12, the air heat exchanger 13 and the compressor 11 in this order.The air heat exchanger 13 is arranged in an outdoor site A (refer to apart surrounded by the dashed-dotted line in FIG. 1), and there isprovided a fan 14 for carrying out heat exchange between the refrigerantand outside air in the air heat exchanger 13. The refrigerant used inthe refrigerant circuit 10 is natural one (for example, carbon dioxide).

The hot water circuit 20 is constituted of a first pump 21, the hotwater storage tank 30 and the water heat exchanger 15; hot watercirculates through the hot water storage tank 30, the first pump 21, thewater heat exchanger 15 and the hot water storage tank 30 in this order.That is, the water heat exchanger 15 is shared by the refrigerantcircuit 10 and the hot water circuit 20; heat exchange is carried outbetween the refrigerant circulating in the refrigerant circuit 10 andthe hot water circulating in the hot water circuit 20.

The hot water storage tank 30 is connected to the hot water circuit 20,and via a first flow path 32 to the water supplying tube 40, and via asecond flow path 33 to the mixing valve 50. Accordingly, low-temperaturewater is supplied from the water supplying tube 40 via the first flowpath 32 to the hot water storage tank 30 and then circulates in the hotwater circuit 20, so that the low-temperature water changes tohigh-temperature water, and thereafter returns to the hot water storagetank 30 to be sent via the second flow path 33 to the mixing valve 50.

The water supplying tube 40 has one end thereof connected to a supplysource such as a water line (not illustrated). And the water supplyingtube 40 has the other end thereof branching into the first flow path 32and a third flow path 34, the water supplying tube 40 is connected viathe first flow path 32 to the hot water storage tank 30, and via thethird flow path 34 to the mixing valve 50. Accordingly, low-temperaturewater is supplied to both the hot water storage tank 30 and the mixingvalve 50 (refer to the arrow of thick line in FIG. 1).

The mixing valve 50 is connected via the second flow path 33 to the hotwater storage tank 30, and via the third flow path 34 to the watersupplying tube 40, and via a fourth flow path 35 to a bathtub 51.Accordingly, high-temperature water supplied via the second flow path 33from the hot water storage tank 30 and low-temperature water suppliedvia the third flow path 34 from the water supplying tube 40 are mixed atthe mixing valve 50 to provide water for bathtub. The water for bathtubprovided at the mixing valve 50 is supplied via the fourth flow path 35to the bathtub 51.

The remote controller 60 is arranged within a bathroom B (refer to apart surrounded by the two-dot chain line in FIG. 1) along with thebathtub 51. The remote controller 60 is provided with an operatingswitch 61 used to start the operation, to adjust the temperature ofwater for bathtub filling the bathtub 51, or to make a water fillingreservation. Operating the operating switch 61 of the remote controller60, the user can start the operation of the hot water device forbathtub, set preset temperature Tb of hot water to be filled into thebathtub 51, or set a start time of filling hot water.

The outdoor air temperature sensor 70 serves to detect outdoor airtemperature Ta being information on outdoor air temperature. Thetemperature of water for bathtub to be supplied to the bathtub 51 isvaried according to outdoor air temperature Ta detected by the outdoorair temperature sensor 70. As the outdoor air temperature sensor 70, anyexisting temperature sensor can be used.

The control-system configuration of the hot water device for bathtubillustrated in FIG. 1 will now be described. The controller 80 acting ascontrol means for controlling the operation of the hot water device forbathtub includes a microcomputer and various types of drivers. Adetection signal is sent to the controller 80 based on outdoor airtemperature Ta detected by the outdoor air temperature sensor 70. Also,a detection signal is sent to the controller 80 based on a water fillingreservation time detected by a timer (not illustrated). According to thedetection signal, the controller 80 controls the opening of the mixingvalve 50 and the supplying of power to the compressor 11, so that thetemperature of water for bathtub to be supplied to the bathtub 51 isvaried as described later.

The operation of the hot water device for bathtub illustrated in FIG. 1will now be described. The control of the hot water device for bathtubby the controller 80 will also be described together.

The refrigerant of the refrigerant circuit 10 circulates through thecompressor 11, the water heat exchanger 15, the expansion valve 12, theair heat exchanger 13 and the compressor 11 in this order (refer to thearrow of solid line in FIG. 1). The hot water of the hot water circuit20 circulates through the hot water storage tank 30, the first pump 21,the water heat exchanger 15 and the hot water storage tank 30 in thisorder (refer to the outlined arrow in FIG. 1).

When the refrigerant and hot water circulate in the respective circuits10 and 20 in this manner, heat exchange is carried out at the water heatexchanger 15 between the refrigerant discharged from the compressor 11and low-temperature water circulating in the hot water circuit 20. Whenheat exchange is carried out at the water heat exchanger 15, thetemperature of hot water circulating in the hot water circuit 20 risesand the high-temperature water is stored in the hot water storage tank30. The high-temperature water stored in the hot water storage tank 30is supplied via the second flow path 33 to the mixing valve 50 (refer tothe arrow of dashed line in FIG. 1).

At the mixing valve 50, the high-temperature water supplied from the hotwater storage tank 30 and the low-temperature water supplied from thewater supplying tube 40 are mixed. In this case, the opening of themixing valve 50 is controlled by the controller 80 according to outdoorair temperature Ta detected by the outdoor air temperature sensor 70, sothat the temperature of water for bathtub to be supplied to the bathtub51 is varied. The control of the opening of the mixing valve 50 by thecontroller 80 will be described below.

First the user operates the operating switch 61 to set presettemperature Tb of hot water filled into the bathtub 51 (step S1).

Subsequently, the controller 80 determines whether the operating switch61 of the remote controller 60 has been turned on by the user (step S2).

At step S2, if the operating switch 61 of the remote controller 60 hasbeen turned on by the user, the controller 80 determines whether or notthe outdoor air temperature sensor 70 has been turned on during the pasthour (step S3). That is, the controller 80 determines whether or not theoutdoor air temperature sensor 70 has been in a state capable ofdetecting outdoor air temperature Ta during the past hour.

Meanwhile, at step S2, if the operating switch 61 of the remotecontroller 60 has not been turned on by the user, the controller 80determines whether or not a water filling reservation time has been set(step S4).

At step S4, if a water filling reservation time has been set, thecontroller 80 determines whether there remain 30 minutes or less untilthe water filling reservation time (step S5). At step S4, if no waterfilling reservation time has been set, the flow returns to step S2.

At step S5, if there remain 30 minutes or less until the water fillingreservation time, the flow returns to step S3. Also, at step S5, if nowater filling reservation time has been set, the flow returns to stepS2.

At step S3, if the outdoor air temperature sensor 70 has been turned onduring the past hour, the controller 80 causes the outdoor airtemperature sensor 70 to detect outdoor air temperature Ta (step S6) andthereafter determines whether or not the detected outdoor airtemperature Ta is equal to or higher than prescribed outdoor airreference temperature T1 (for example, T1=35° C.) (step S7).

Meanwhile, at step S3, if the outdoor air temperature sensor 70 has notbeen turned on during the past hour, the outdoor air temperature sensor70 is turned on so that outdoor air temperature Ta can be detected (stepS8), and the flow returns to step S6.

At step S7, if the detected outdoor air temperature Ta is equal to orhigher than a prescribed outdoor air reference temperature T1, thecontroller 80 controls the opening of the mixing valve 50 so that thetemperature of water for bathtub becomes lower by a predetermined value(for example, 2° C.) than hot water filling preset temperature Tb, andvaries the temperature of water for bathtub to temperature Tc desired bythe user during bathing (step S9). That is, when high-temperature waterand low-temperature water is mixed at the mixing valve 50, the openingof the mixing valve 50 is controlled by the controller 80 so that thetemperature of water for bathtub to be supplied to the bathtub 51becomes Tc lower by 2° C. than hot water filling preset temperature Tb,and thus more low-temperature water is imported.

Meanwhile, at step S7, if the detected outdoor air temperature Ta is notequal to or higher than prescribed outdoor air reference temperature T1,it is determined whether the detected outdoor air temperature Ta isequal to or higher than prescribed outdoor air reference temperature T2(for example, T2=30° C.) and at the same time lower than prescribedoutdoor air reference temperature T1 (step S10).

At step S10, if the detected outdoor air temperature Ta is equal to orhigher than prescribed outdoor air reference temperature T2 and at thesame time lower than prescribed outdoor air reference temperature T1,the controller 80 controls the opening of the mixing valve 50 so thatthe temperature of water for bathtub becomes lower by a predeterminedvalue (for example, 1° C.) than hot water filling preset temperature Tb,and varies the temperature of water for bathtub to temperature Tddesired by the user during bathing (step S11). That is, whenhigh-temperature water and low-temperature water is mixed at the mixingvalve 50, the opening of the mixing valve 50 is controlled by thecontroller 80 so that the temperature of water for bathtub to besupplied to the bathtub 51 becomes Td lower by 1° C. than hot waterfilling preset temperature Tb, and thus more low-temperature water isimported.

Meanwhile, at step S10, if the detected outdoor air temperature Ta isequal to or higher than prescribed outdoor air reference temperature T2and at the same time not lower than prescribed outdoor air referencetemperature T1, it is determined whether or not the detected outdoor airtemperature Ta is equal to or higher than prescribed outdoor airreference temperature T3 (for example, T3=20° C.) and at the same timelower than prescribed outdoor air reference temperature T2 (step S12).

At step S12, if the detected outdoor air temperature Ta is equal to orhigher than prescribed outdoor air reference temperature T3 and at thesame time lower than prescribed outdoor air reference temperature T2,the temperature of water for bathtub is varied to temperature Te equalto hot water filling preset temperature Tb (step S13). That is, if thedetected outdoor air temperature Ta is equal to or higher thanprescribed outdoor air reference temperature T3 and at the same timelower than prescribed outdoor air reference temperature T2, thetemperature adjustment relative to hot water filling preset temperatureTb is not made.

Meanwhile, at step S12, if the detected outdoor air temperature Ta isequal to or higher than prescribed outdoor air reference temperature T3and at the same time not lower than prescribed outdoor air referencetemperature T2, it is determined whether or not the detected outdoor airtemperature Ta is equal to or higher than prescribed outdoor airreference temperature T4 (for example, T4=10° C.) and at the same timelower than prescribed outdoor air reference temperature T3 (step S14).

At step S14, if the detected outdoor air temperature Ta is equal to orhigher than prescribed outdoor air reference temperature T4 and at thesame time lower than prescribed outdoor air reference temperature T3,the controller 80 controls the opening of the mixing valve 50 so thatthe temperature of water for bathtub becomes higher by a predeterminedvalue (for example, 1° C.) than hot water filling preset temperature Tb,and varies the temperature of water for bathtub to temperature Tfdesired by the user during bathing (step S15). That is, whenhigh-temperature water and low-temperature water is mixed at the mixingvalve 50, the opening of the mixing valve 50 is controlled by thecontroller 80 so that the temperature of water for bathtub to besupplied to the bathtub 51 becomes Tf higher by 1° C. than hot waterfilling preset temperature Tb, and thus more high-temperature water isimported.

Meanwhile, at step S14, if the detected outdoor air temperature Ta isequal to or higher than prescribed outdoor air reference temperature T4and at the same time not lower than prescribed outdoor air referencetemperature T3, it is determined whether or not the detected outdoor airtemperature Ta is lower than prescribed outdoor air referencetemperature T4 (step S16).

At step S16, if the detected outdoor air temperature Ta is lower thanprescribed outdoor air reference temperature T4, the controller 80controls the opening of the mixing valve 50 so that the temperature ofwater for bathtub becomes higher by a predetermined value (for example,2° C.) than hot water filling preset temperature Tb, and varies thetemperature of water for bathtub to temperature Tg desired by the userduring bathing (step S17). That is, when high-temperature water andlow-temperature water is mixed at the mixing valve 50, the opening ofthe mixing valve 50 is controlled by the controller 80 so that thetemperature of water for bathtub to be supplied to the bathtub 51becomes Tg higher by 2° C. than hot water filling preset temperature Tb,and thus more high-temperature water is imported. Meanwhile, at stepS16, if the detected outdoor air temperature Ta is not lower thanprescribed outdoor air reference temperature T4, and the flow returns tostep S7.

The water for bathtub having its temperature varied as described aboveto temperature Tc, Td, Te, Tf or Tg (Tc<Td<Te<Tf<Tg) desired by the userduring bathing in the mixing valve 50 according to the detected outdoorair temperature Ta is supplied via the fourth flow path 35 to thebathtub 51 (refer to the arrow of dashed-dotted line in FIG. 1) to startautomatic filling of hot water.

In this way, according to the hot water device for bathtub of thepresent embodiment, the water for bathtub having its temperature variedby the controller 80 to temperature Tc, Td, Te, Tf or Tg desired by theuser during bathing is supplied to the bathtub 51. Accordingly, thetemperature adjustment using water is not needed, and thus water is notwasted to allow energy saving and at the same time it is possible tosave a trouble of adjusting the temperature of hot water in the bathtubto a temperature desired by the user during bathing.

Also, according to the hot water device for bathtub of the presentembodiment, since any existing temperature sensor can be used as theoutdoor air temperature sensor 70, component cost can be suppressed.

According to the above embodiment, as the outdoor air temperatureinformation acquiring means, the outdoor air temperature sensor 70detecting outdoor air temperature Ta is used, but the outdoor airtemperature information acquiring means is not limited thereto as longas information on outdoor air temperature Ta can be acquired. Forexample, the outdoor air temperature information acquiring means mayacquire outdoor air temperature Ta from predetermined meteorologicaldata.

According to the above embodiment, the temperature of water for bathtubsupplied to the bathtub 51 is varied according to outdoor airtemperature Ta detected by the outdoor air temperature sensor 70, butthe present invention is not limited thereto. For example, the operationof the compressor 11 or the first pump 21 may be controlled according tooutdoor air temperature Ta detected by the outdoor air temperaturesensor 70, in this case, energy saving can also be achieved in storinghigh-temperature water in the hot water storage tank 30.

Further, according to the above embodiment, heat exchange is carried outbetween the refrigerant circulating in the refrigerant circuit 10 usingexternal heat and the hot water circulating in the hot water circuit 20,but the present invention is not limited thereto. For example, the heatexchange of hot water may be carried out by a gas hot water device orthe like.

1. A hot water device for bathtub comprising: a hot water storage tankwhich stores high-temperature water; water supplying means for supplyinglow-temperature water; and temperature setting means allowing setting ofthe temperature of water for bathtub to be supplied to a bathtub, thehot water device for bathtub mixing high-temperature water supplied fromthe hot water storage tank and low-temperature water supplied from thewater supplying means and then supplying water for bathtub of a presettemperature to the bathtub, wherein the hot water device for bathtubincludes outdoor air temperature information acquiring means foracquiring prescribed information on outdoor air temperature; and controlmeans for varying the temperature of water for bathtub to a temperaturelower than the preset temperature when the outside air temperatureacquired by the outdoor air temperature information acquiring means ishigher than a prescribed reference temperature, or varying thetemperature of water for bathtub to a temperature higher than the presettemperature when the outside air temperature acquired by the outdoor airtemperature information acquiring means is lower than the prescribedreference temperature.
 2. The hot water device for bathtub according toclaim 1, further comprising a mixing valve which mixes high-temperaturewater supplied from the hot water storage tank and low-temperature watersupplied from the water supplying means to produce water for bathtub,wherein the control means controls the opening of the mixing valve andthereby varies the preset temperature of water for bathtub to besupplied to the bathtub.
 3. The hot water device for bathtub accordingto claim 1, wherein an outdoor air temperature sensor constitutes theoutdoor air temperature information acquiring means.
 4. The hot waterdevice for bathtub according to claim 1, wherein the outdoor airtemperature information acquiring means acquires an outdoor airtemperature from predetermined meteorological data.
 5. The hot waterdevice for bathtub according to claim 2, wherein an outdoor airtemperature sensor constitutes the outdoor air temperature informationacquiring means.
 6. The hot water device for bathtub according to claim2, wherein the outdoor air temperature information acquiring meansacquires an outdoor air temperature from predetermined meteorologicaldata.